Roof span and support

Hello all,

I attached a picture of our barn with dimensions. I'd like to know whether a building of those dimensions should have some sort of interior wall support, or should a span and pitch such as that generally be fine on its own.

It is an old barn, and the roof rafters are 2"x6" roughly 24" on centre. This wood is actually a full 2" and 6", so it's not your standard 2x6 size.

On the inside of the barn there is a metal pipe that runs the length of the barn on both sides about half way up on the rafters. And every 15'-20' there is a vertical steel pipe that goes from the ground up to the horizontal pipe that runs the length of the barn for support. So it is essentially a pipe frame that's on the inside of the barn that supports the roof rafters about half way up. We never could figure whether this 'frame' was there for another purpose, or that frame is actually there meant for structural support.

In the middle of the barn on one side, we cut out 2 of the vertical supports and are sectioning off an area for storage with a 2x6 wall.

My questions are:

1. Without those support pipes, would a structure of this size usually need those interior supports, or are those in there just for extra precaution?

2. We are going to make a 2x6 wall from the floor to the roof, with a 'top plate' that runs the length of the room along the roof rafters. So our 2x6 wall will structurally replace the 2 vertical steel pipes that used to be there. The 2x6 vertical wall studs will fasten to this top plate. Should it be a double top plate, or will this be plenty of structural support?

I can draw up another sketch or take actual pictures if what I explained was unclear.

Roof span and support

So this is how we're attaching the vertical wall studs to the roof rafters. Is a single top plate like this ok?

Keep in mind that the roof rafters are 24" on center, and the vertical wall studs are going to be 16" on center. So that means that some of the vertical studs will be in the middle of the roof rafters. So considering that, is a single 2x6 'top plate' enough, or should it be doubled?

Roof span and support

Don't think I have ever seen pipe on the horizontal axis being used as a structural member. I would have to venture a guess that this horizontal pipe is fastened some how to the rafter?

By your description is sound like it is being used a strutural support, but experience tells me its not a very good one, although we don't know what size and type this pipe is.

As a general rule these types of questions are better left answered by a local qualified builder or engineer the latter being the best.

The forces which act on a structure like yours (without horizontal ties) is outward as well as vertically down. The type of support you are describing only supports vertically.

How are the walls? are they pushing outward on this structure?

Are there actually no horizontal ties?

I wouldn't remove anything until someone qualified looks at it.

Mark

The walls are concrete blocks. It appears like the horizontal pipe is just fastened by clips of some sort along the rafters, and then every 15'-20' there are the vertical pipes that just go into the dirt floor of the barn.

There are horizontal ties, I should have mentioned that. They are on about every 7th or 8th roof rafter approx, I'd have to run out and check. But there are ties that go across from one side of the roof rafter to the other.

Thanks for your help, I do appreciate it.

Maybe I should go out and snap a few pictures in case what I've described isn't all that clear..